TECHNOLOGIES are often billed as transformative. For William Kochevar, the term is justified. Mr Kochevar is paralysed below the shoulders after a cycling accident, yet has managed to feed himself by his own hand. This remarkable feat is partly thanks to electrodes, implanted in his right arm, which stimulate muscles.

Together, technology and teachers can revamp schoolIN 1953 B.F. Skinner visited his daughterâ€™s maths class. The Harvard psychologist found every pupil learning the same topic in the same way at the same speed. A few days later he built his first â€œteaching machineâ€, which let children tackle questions at their own pace. By the mid-1960s similar gizmos were being flogged by door-to-door salesmen. Within a few years, though, enthusiasm for them had fizzled out.

How to improve the health of the oceanThe ocean sustains humanity. Humanity treats it with contemptEARTH is poorly named. The ocean covers almost three-quarters of the planet. It is divided into five basins: the Pacific, the Atlantic, the Indian, the Arctic and the Southern oceans. Were all the planetâ€™s water placed over the United States, it would form a column of liquid 132km tall. The ocean provides 3bn people with almost a fifth of their protein (making fish a bigger source of the stuff than beef). Fishing and aquaculture assure the livelihoods of one in ten of the worldâ€™s people. Climate and weather systems depend on the temperature patterns of the ocean and its interactions with the atmosphere. If anything ought to be too big to fail, it is the ocean.

Why Israel needs a Palestinian stateMore than ever, land for peace also means land for democracyTHE victory of Israel over the Arab armies that encircled it in 1967 was so swift and absolute that, many Jews thought, the divine hand must have tipped the scales. Before the six-day war Israel had feared another Holocaust; thereafter it became an empire of sorts.